JUST the other night, while reversing into a lot, the Caliber's rear-view camera caught a litter bug in action. The lout obviously thought no one saw him, as he sneakily placed a disposable cup on the kerb before slithering into his car and driving off.

The carpark had litter bins within a few steps in every direction, and yet this man, who was with a woman, chose sloth over civility.

Even though it was dark, the reverse camera - part of a Pioneer entertainment set we installed in April - picked up the act. If only it had a recording function.

Motorists, as you might know, are among the worst litterers on the island. Just look at the confetti of parking coupon tabs in every public carpark. Along with soiled tissues, cigarette butts, half-eaten packets of noodles (flung out of moving truck) and, yes, disposable cups.

People here apparently not only become ogres behind the wheel, but they also tend to become filthy ogres.

If you, like me, believe that cleanliness is next to godliness, then you share my loathing. And you will probably appreciate the latest treatment we have given our long-term test Dodge.

It is a relatively new application that renders a car's interior more impervious to lingering odours and toxic compounds. It claims to be detrimental to bacteria, virus and fungus too.

The treatment, provided by Hycare, coats the car interior with a thin layer of titanium dioxide. The substance, commonly used as a food additive, is a photocatalyst.

That's a fancy way of saying it has the ability to accelerate the breakdown of substances (such as smells) in its vicinity whenever there is light.

In Japan, this process is used widely to keep taxis and buses clean and odourless. It gained prominence in 2003, when it was used to help combat the Sars outbreak.

It took about two hours for the Dodge to be treated. First, the cabin was properly wiped down and vacuumed. Then an undercoating is applied to the cabin surfaces.

When this dries, the titanium dioxide coating is sprayed on. The undercoating is needed because titanium dioxide can corrode some materials.

Stay tuned for the next instalment, when we report on how the treated car stands up to the king of odours: durian.

It would probably be the final instalment of the Dodge Dare. We took the car in February from DaimlerChrysler, but will be returning it to what will soon be known as Chrysler Holding.

It's amazing what can happen in five months.

Meanwhile, if you want more details on the titanium dioxide process, log on to www.hycare.org.

The Dodge Caliber is powered by Caltex with Techron